Use dax_is_supported() to validate whether the architecture has
virtually aliased data caches at mount time. Print an error and disable
DAX if dax=always is requested as a mount option on an architecture
which does not support DAX.
This is relevant for architectures which require a dynamic check
to validate whether they have virtually aliased data caches.
Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Gao Xiang <xiang@xxxxxxxxxx>
Cc: Chao Yu <chao@xxxxxxxxxx>
Cc: Yue Hu <huyue2@xxxxxxxxxxx>
Cc: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
Cc: linux-erofs@xxxxxxxxxxxxxxxx
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: nvdimm@xxxxxxxxxxxxxxx
Cc: linux-cxl@xxxxxxxxxxxxxxx
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
---
fs/erofs/super.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 3789d6224513..82e569bd5889 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -644,7 +644,10 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
}
if (test_opt(&sbi->opt, DAX_ALWAYS)) {
- if (!sbi->dax_dev) {
+ if (!dax_is_supported()) {
+ errorfc(fc, "DAX unsupported by architecture. Turning off DAX.");
+ clear_opt(&sbi->opt, DAX_ALWAYS);
+ } else if (!sbi->dax_dev) {
errorfc(fc, "DAX unsupported by block device. Turning off DAX.");
clear_opt(&sbi->opt, DAX_ALWAYS);
} else if (sbi->blkszbits != PAGE_SHIFT) {
--
2.39.2
